Jonner et al., "Electrohydraulic Brake System--The First Approach to Brake-By-Wire Technology," SAE (Society of Automotive Engineers) Technical Paper Series, Paper No. 960991, 1996, pp. 105-112 describes a conventional electrohydraulic braking system, in which a driver braking input is derived from the actuation of the brake pedal by the driver. This braking input is converted, possibly in view of further operating variables, into setpoint brake pressures for the individual wheel brakes. The setpoint braking pressures are adjusted for each wheel by closed pressure-control loops as a function of the predefined setpoint pressure, and of the actual brake pressure measured in the area of the wheel brake. Since, in such an electrohydraulic braking system, the brake pressure in the wheel brakes is adjusted and modulated by electrical means via valve arrangements, dependent upon the driver's braking input, in case of a fault, secondary braking operations must be guaranteed which assure a sufficient braking action, even in the event of a fault. The proposal in this connection for the conventional braking system is switching off the electrical system and switching over to a hydraulic brake, or the electrical operation of only three wheel brakes. With these means, most faults can be satisfactorily mastered, though nevertheless, in some cases, a switch-over is made to hydraulic operation.